should i install the methanol injection into my 93 mazda. any recommen what ii should do if my engine get too hot, i kno using bigger injection and E85 will cool its down like at least 20 degree. and one more thing when i try to boost on the first gear and second it feel like kind of stuck on gas.

 

Is this car stock? Lightly modified? Heavily modified? If modified, list things like turbo, injector sizes, EMS, boost level etc...

Methanol injection does not lower engine temperature persay; it lowers intake air temperatures & therefore exhaust gas temperatures. Knock resistance is increased. Larger injectors are not there to cool the engine down either, but increasing fuel delivery amount will lower IATs and EGTs somewhat. But larger injectors should never be added to a car that has no way to adjust injector duty cycles. The stock ECU would have no way to know the injector size changed, and you would run excessively rich.

There is a whole section dedicated to aux. injection: https://www.rx7club.com/auxiliary-injection-173/. For vehicles using a stock ECU, water injection is the best route. Fuel delivery does not need to be changed if injecting water alone, and water has the highest latent heat of vaporization (cooling ability).

E85 is used for added knock resistance (due to high ethanol levels), and the ethanol also has a greater cooling effect than straight gasoline (like methanol), but the engine would need to be re-tuned to take full advantage, and fuel lines would need to be upgraded to handle the ethanol. Fuel efficiency will also decrease, as the ratio of E85 to air is higher than with gasoline. Again, if the car has a stock ECU, there isn't much to be gained from just adding E85.

If you want information on reducing overall engine temperatures, check the 3rd gen FAQ for "reliabilty mods". Lower temperature fan switches and upgraded radiators are some of the ways to accomplish this.